It varies depending on the item. Pool cleaners tend to look very different from each other, so I am looking for several different ones. Whereas brushes all look more or less the same, so there will probably only be one (or maybe two) brush pictures. There are many kinds of pool covers, so one of each type. Probably two different styles of each type of filter. And so on.
There are two goals for the encyclopedia. One is for times when something is mentioned on the forum that you have never heard of. You can go to the encyclopedia and see a picture of it. The other is for people who see some piece of pool equipment, perhaps at a house they just bought, and don't know what it is. They can go to the encyclopedia and look around for a picture of something similar and at least know what to call it so they can ask a question about it on the forum.
For example, people often don't know what borax looks like, so they can find it in the grocery store. Or they have a vacuum plate, but have no idea what it is or what it does.
There are two goals for the encyclopedia. One is for times when something is mentioned on the forum that you have never heard of. You can go to the encyclopedia and see a picture of it. The other is for people who see some piece of pool equipment, perhaps at a house they just bought, and don't know what it is. They can go to the encyclopedia and look around for a picture of something similar and at least know what to call it so they can ask a question about it on the forum.
For example, people often don't know what borax looks like, so they can find it in the grocery store. Or they have a vacuum plate, but have no idea what it is or what it does.